Mycoplasma genitalium identified in one-third of men with symptomatic non-gonococcal urethritis, with at least 40% of cases demonstrating macrolide resistance

ABSTRACT

Background: In recent years there has been increased awareness of Mycoplasma genitalium as a potential sexually-transmitted pathogen and national guidelines now recommend routine testing in a number of clinical scenarios in sexual health clinics, including non-gonococcal urethritis (NGU). Factors including availability and cost of resistance testing, quinolone-associated toxicities and a lack of available alternative treatments, all impact on the feasibility of routine testing. Knowledge of local prevalence and rates of drug resistance can inform the development of patient pathways and management strategies. The aim was to determine the prevalence of Mycoplasma genitalium in men with symptomatic NGU and the proportion of these infections that demonstrated macrolide resistance. Method: Routine testing for Mycoplasma genitalium in symptomatic NGU was introduced in August 2020, during a period when walk-in attendances were limited due to the COVID-19 pandemic. Testing was performed inhouse using the validated Roche Cobas® TV/MG PCR assay and positive samples were tested for the macrolide resistance gene using SpeeDx Resistanceplus® MG. Quinolone resistance testing was not routinely performed. Clinical information including patient demographics, treatments used, test of cure (TOC) results and coding data were reviewed and analysed. Results: 42 symptomatic men presented during August 2020 and were diagnosed with NGU. 34 (81%) had testing performed for Mycoplasma genitalium, 10/34 (29%) tests were positive. Resistance testing was performed on all positive samples, 4 (40%) were positive for macrolide resistance;2 (20%) were indeterminate and 4 (40%) were negative. All patients were treated with regimens according to BASHH guidelines and 1 (10%) patient had a positive TOC. Conclusion: High rates of Mycoplasma genitalium were identified when screening men with symptomatic urethritis in a central London sexual health clinic. In this population, at least 40% of infections had macrolide resistance demonstrated. The majority of individuals cleared the pathogen with symptom resolution and a negative TOC using recommended treatment regimens. Larger surveys in different populations will enhance knowledge of risk factors associated with Mycoplasma genitalium infection and antibiotic resistance. Further study of alternative treatment approaches for drug-resistant organisms are required.